Chocolate, which is made mostly from cacao beans, is a highly palatable food item having a good flavor and a good melt-in-the-mouth-property. A tempered chocolate known as chocolate of general type (including chocolate containing only cocoa butter contained in cacao beans as an oil and fat component) is usually obtained by subjecting chocolate mix in a melted state obtained from chocolate raw materials to a tempering operation, followed by cooling solidification of the chocolate mix.
A tempering operation is an operation to generate a crystal core of a stable crystal in chocolate mix in a melted state, in order to solidify cocoa butter which can take various crystal structures as a stable crystal. Concretely, for instance, tempering is known as an operation where chocolate mix in a melted state at a temperature of 40 to 50° C. is cooled down to the temperature of about 27 to 28° C. and, then, heated again up to about 29 to 31° C.
When an amount of a stable crystal generated in a tempering operation is appropriate, a solidification speed in cooling chocolate mix becomes faster, so that sufficient contraction occurs while the chocolate mix solidifies. Further, chocolate after solidification is easily released from a mold (namely, good in mold releasing property), generation of fat bloom (referring to a phenomenon in which white crystal of oil and fat generates on a surface of chocolate and hereinafter referred to as “bloom”) is suppressed, and chocolate with good gloss is obtained. Furthermore, bloom resistance during storage of the obtained chocolate is also good.
On the other hand, if an amount of a stable crystal generated in a tempering operation is small, bloom tends to generate, which results in lowered bloom resistance during the storage of the obtained chocolate, so that bloom may generate in a short period. Furthermore, if an amount of a stable crystal generated in a tempering operation is large, the texture of the obtained chocolate becomes rough, which may lower bloom resistance during storage of chocolate. Therefore, control of a tempering operation is very important in the production of chocolate.
As a method for performing a tempering operation conveniently, a method referred to as “a seeding method” or “seeding” is known, where a stable crystal of a symmetrical triacylglycerol etc. is added to chocolate mix as a seeding agent. Since the seeding agent functions as a crystal core for a stable crystal, a tempering operation can be carried out conveniently by means of the seeding agent. As a seeding method, a method where, for instance, a crystal of 1,3-distearoly-2-oleoylglycerol (StOSt) or 1,3-dibehenyl-2-oleolyglycerol (BOB) is added as a seeding agent has been developed (for instance, Patent Literatures 1 to 5).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. S63-240745
Patent Document 2: Japanese Unexamined Patent Application, Publication No. S64-060330
Patent Document 3: Japanese Unexamined Patent Application, Publication No. H02-000406
Patent Document 4: Japanese Unexamined Patent Application, Publication No. H02-242639
Patent Document 5: Japanese Unexamined Patent Application, Publication No. 2008-005745